1. Field of the Invention
The invention relates to a method and apparatus for stripping fibrin and thrombus build-up from a catheter. More specifically, the invention relates to a method and apparatus employing a shape memory or super-elastic stripping coil to strip fibrin build-up from both the interior and exterior of a dialysis catheter.
2. Description of the Prior Art
The use of long and short term, implanted catheters has become commonplace in the practice of medicine. These catheters are commonly formed of biocompatible plastic materials and are implanted to relieve various symptoms and/or to assist in medical procedures. For example, dialysis catheters are commonly implanted to facilitate simplified dialysis procedures for those patients requiring such assistance.
The use of these catheters is not without problems. For example, these biocompatible plastic catheters are susceptible to the formation of deposits of fibrin and platelets, referred to as fibrin sheaths. Such fibrin sheaths commonly form along the open free end of an implanted dialysis catheter, covering both the exterior and interior surfaces of the catheter.
As those skilled in the art appreciate, the build-up of such fibrin sheaths is undesirable and can cause catheter dysfunction. Once the presence and extent of the fibrin sheath have been identified, the physician must take the necessary steps to remove the sheath from the implanted catheter. While it is conceivable that the implanted catheter may be removed and replaced surgically, it is more desirable for the fibrin sheath to be removed without surgical removal of the implanted catheter.
Various techniques have been developed for the removal of such sheaths; however, no prior technique has been able to effectively remove the fibrin sheath from the outer surface of the catheter in a convenient and reliable manner causing minimal trauma to the patient. The present invention provides an apparatus and method overcoming the shortcomings of these prior art devices.